Neurofibromatosis Type 1 (NF1) is a common autosomal dominant neurocutaneous syndrome. NF1 has range of phenotypic expression, with neurological abnormalities often present, including high signal intensity foci on T2 weighted images and megalencephaly (increased brain volume). However, the most common concern of parents with children with NF1 is learning disabilities (LDs). Approximately half of children with NF1 have LDs, the most debilitating and common of which are reading disabilities. The overall purpose of this research is to gain a deeper understanding of the characteristics and treatment of reading disabilities in NF1. The first goal is to determine whether children with NF1 who have specific deficits in reading respond the same way, both neurobiologically and neuropsychologically, to specialized treatment known to ameliorate decoding deficits in reading in the general population; an additional goal is to determine which type of intervention is the best for particular type of learner profiles. To accomplish these goals, we will compare children with NF1 who show weaknesses in reading to children with reading disabilities from the general population pre and post two different types of intervention, using both behavioral and neurobiological (fMRI) measures. Both interventions focus on teaching sound-symbol relationships, but vary in terms of relative emphasis on verbal versus visual methods of teaching. Determining if children with NF1 with deficits in reading respond to interventions known to be effective for children with reading disabilities in the general population, and, in particular, which type of intervention approach they respond to best, will advance knowledge about the best therapies for LDs in NF1. Another goal of this research is to determine further the similarities/differences between the cognitive profiles of children with NF1 who have reading disabilities, versus children with reading disabilities in the general population; in particular, this is to determine if interventions developed for other deficits in reading disabilities, besides decoding, will also be useful for children with NF1 who show weaknesses in reading. Finally, we will characterize the neuropsychological and neurobiological differences between children with NF1 who have reading disabilities, versus children with NF1 without a reading disability; the goal of this last aim is to gain an understanding of which factors may serve as "protective" factors in NF1, in terms of developing reading problems. This research utilizes what is known about treatment of LDs in the general population, as well as fMRI methodology, which will further our understanding of how the NF1 gene affects cognition and the brain. Additionally, this research is also highly valuable because it will further our knowledge about effective treatments for reading disabilities in general. [unreadable] [unreadable] [unreadable]